Regulation system for the hydraulic control of braking of a vehicle with pneumatic tires

Claim 2

A regulation system for the control of braking of a vehicle with pneumatic tires, said system comprising first, second and third regulation circuits and a slip computer, said first regulation circuit generating a signal which is a function of the deceleration of the vehicle and of the pilot''s braking effort, said second circuit being for integral regulation with respect to a slip having a predetermined reference value proportional to a signal representing the pilot''s braking effort, and said third circuit being for regulation as a function of the slip, with said circuit having continuously variable gain, said computer being connected to said circuits to receive at its inputs signals representing the angular speed omega of the vehicle and of a braked wheel and multiplying their difference by the sum of a constant and a factor proportional to omega reduced by a factor proportional to the logarithm of omega to provide an output signal representing wheel slip, the outputs of said regulation circuits and computer being employed to effect brake action.

Claim 3

A regulation system as claimed in claim 1, in which said first regulation circuit has two levels of gain for the pilot''s signal and for a signal representing the vehicle speed, and means for reducing said two gains when the slip exceeds the value of a reference slip.

Claim 4

A regulation system as claimed in claim 2 comprising means for locking said reductions of gain after a predetermined time-delay.

Claim 5

A regulation system as claimed in claim 1, further comprising two devices coupled to said regulation circuits to render said regulation circuits inoperative at low running speeds of said vehicle.

Claim 6

A regulation system as claim in claim 1, in which said first regulation circuit comprises a band-pass filter at the input of said vehicle-speed signal.

Claim 7

A regulation system as claim in claim 5, in which said band-pass filter comprises a transistor to which signals are applied in opposition on its base and its collector, a condenser connected between the emitter and collector of said transistor, a potentiometer connected between the emitter and said base, the output being taken from the slider of said potentiometer with filtration by condensers and resistances.

Claim 8

A regulation system as claim in claim 1, in which the first regulation circuit comprises two differentiators for differentiating said vehicle-speed signal as a function of time, one for accelerations, the other for decelerations, the outputs of said differentiators being applied in parallel to a comparison device, together with the pilot''s signal.

Claim 9

A regulation system as claimed in claim 1, in which, for the calculation of the logarithm of omega , said computer comprises an amplifier with negative feedback and two inputs of which one is grounded, connected to the two emitters of a double transistor having one collector connected to the input of said amplifier, one base connected to ground, the other collector and the other base being coupled to an output amplifier.

Claim 10

A regulation system as claimed in claim 1, in which said third circuit includes a parabolic amplifier which comprises a transistor having the input signal applied to its base through a bridge having three arms connected in parallel, one arm comprising a resistance, the second arm comprising a diode in series with a second resistance, and the third arm comprising two diodes in series with a third resistance.

Claim 11

A regulation system for the control of braking of a vehicle with pneumatic tires, said system comprising first, second and third regulation circuits and a slip computer, said first regulation circuit generating a signal corresponding to a function of the deceleration of the vehicle and of the pilot''s braking effort, said first circuit having two levels of gain for the signal representing pilot''s braking effort and for the vehicle-speed signal, these two gains being reduced when the slip exceeds a reference value, said reductions in gain being locked after a predetermined time-delay, said first circuit comprising a band-pass filter at the input of the vehicle-speed signal, said band-pass filter comprising a transistor to which signals are applied in opposition on its base and on its collector, a condenser between the emitter and the collector, a potentiometer between the emitter and the base, the output being taken from the slider of said potentiometer with filtration by condensers and resistances, said first circuit further comprising two differentiators for differentiating the vehicle-speed signal as a function of time, one for accelerations, the other for decelerations, the outputs of said differentiators being applied in parallel to a comparison device simultaneously with the pilot''s signal, said computer comprising, for the calculation of the logarithm of an amplifier with negative feedback and two inputs of which one is grounded, connected to the two emitters of a double transistor having one collector coupled to the input of said amplifier, one base being connected to ground, the other collector and the other base being coupled to an output amplifier, said second circuit being for integral regulation with respect to a predetermined reference slip proportional to the pilot''s signal with two devices for rendering inoperative said regulation circuits at low speeds, said third regulation circuit acting as a function of the slip, with continuously variable gain of parabolic form, said computer receiving at its inputs the angular speed signals omega of the vehicle and of a braked wheel, and multiplying their difference by the sum of a constant and a factor proportional to omega reduced by a factor proportional to the logarithm of omega to provide an output signal representing wheel slip, the output signals of said regulation circuits and computer being employed to effect brake action, said parabolic amplifier comprising a transistor having the input applied to its base through a bridge having at least three arms connected in parallel, one arm comprising a resistance, the second arm comprising a diode in series with a second resistance, and the third arm comprising two diodes in series with a third resistance.

Claim 12

A regulation system for the control of braking of a vehicle with pneumatic tires, said system comprising first, second and third regulation circuits and a slip computer, said first regulation circuit generating a signal corresponding to a function of the deceleration of the vehicle and of the pilot''s braking effort, said first circuit having two levels of gain for the signal representing pilot''s braking effort and for the vehicle-speed signal, these two gains being reduced when the slip exceeds a reference value, said reductions in gain being locked after a predetermined time-delay, said first circuit comprising a band-pass filter at the input of the vehicle-speed signal, said band-pass filter comprising a transistor to which signals are applied in opposition on its base and on its collector, a condenser between the emitter and the collector, a potentiometer between the emitter and the base, the output being taken from the slider of said potentiometer with filtration by condensers and resistances, said first circuit further comprising two differentiators for differentiating the vehicle-speed signal as a function of time, one for accelerations, the other for decelerations, the outputs of said differentiators being applied in parallel to a comparison device simultaneously with the pilot''s signal, said computer comprising, for the calculation of the logarithm of an amplifier with negative feedback and two inputs of which one is grounded, connected to the two emitters of a double transistor having one collector coupled to the input of said amplifier, one base being connected to ground, the other collector and the other base being coupled to an output amplifier, said second circuit being for integral regulation with respect to a predetermined reference slip proportional to the pilot''s signal with two devices for rendering inoperative said regulation circuits at low speeds, said third regulation circuit acting as a function of the slip, with continuously variable gain of parabolic form, said computer receiving at its inputs the angular speed signals omega of the vehicle and of a braked wheel, and multiplying their difference by the sum of a constant and a factor proportional to omega reduced by a factor proportional to the logarithm of omega to provide an output signal representing wheel slip, the output signals of said regulation circuits and computer being employed to effect brake action, said parabolic amplifier comprising a transistor having the input applied to its base through a bridge having at least three arms connected in parallel, one arm comprising a resistance, the second arm comprising a diode in series with a second resistance, and the third arm comprising two diodes in series with a third resistance.